Selenium dioxide as a selenylating reagent: An overview and its Sanguine future

Abstract

Selenylation of heterocyclic and carbocyclic compounds using selenium dioxide as a selenylating reagent has emerged as a novel research area. Selenium dioxide is a cheap, easily available and odorless selenium source with wide functional group tolerance. Selenium dioxide is much known for α‐oxidation reactions but this review will elaborate its role as oxidizing as well as selenylating agents. In this review, we have summarized the selenylation of different molecules like anilines, phenylhydrazines, aryl alkyl ketones, phenols, indoles, active methylene compounds, imidazole heterocycles, 1,3‐diones, boronic acids, pyrazoles, 2‐hydroxy acetophenones, alkyl halides and different electron rich arenes along with detailed mechanism. Triselenium dicyanide is a yellow colored addition product that has now been emerged as a well‐known reagent of selenocyanation and many research groups extensively working on it. Selenium containing compounds possess biological as well as pharmacological activity. The immense potential of selenium dioxide as a selenylating reagent attracted the interest of researchers working on selenylation.